The problem of interest is related to the multi-channel audio coding method described in [1,2]. In a nutshell, the idea is to describe multi-channel audio content as a down-mixed (mono) channel along with a set of cues referred to as “inter-channel level difference” (ICLD) and “inter-channel time difference” (ICTD). These cues have been shown to well capture the spatial correlation between the microphone signals [1]. The mono signal and the cues are transmitted by an encoder to a decoder. This latter retrieves the original multi-channel audio signals by applying these cues on the received mono signal.
The direct use of this method for our application is however not possible since the signals of interest (left and right hearing aids) are not available centrally. The cues must thus be computed in a “distributed” fashion. This involves the use of a rate-constrained wireless communication link which entails coding methods, such as the one presented here, that target low communication bit-rates and low delays. Moreover, the goal of the proposed scheme is not to retrieve a multi-channel audio input from a down-mixed signal, as it is the case in [1,2], but the left (resp. right) audio channel using the right (resp. left) audio input. This requires the development of novel reconstruction methods specifically tailored for this purpose.